Electronic components generate heat. In those electronic devices that house a large number of electronic components in a comparatively narrow housing, such as personal computers, LAN servers, copiers, and the like, there is a risk that heat generated by the electronic components will be accumulated inside the housing causing the internal temperature of such devices to rise to unacceptable levels and, thereby, causing the device to malfunction or causing the components within them to fail. Accordingly, ventilation holes are provided, for example, in the wall surface of the housing of such electronic devices and a blower is installed in the ventilation hole to remove heat from the housing. Additionally, blowers may be configured to cool such devices or specific components within them by blowing cool air into such devices.
The size constraints of the blowers used to remove heat from electronic devices or to cool electronic devices, as well as the airflow and discharge pressure requirements for such blowers are dependent upon the dimensions of the housing in which the blower is mounted, the quantity of heat generated inside the housing, and the density of the electrical components within the housing. Fine adjustments to a blower's output characteristics are sometimes necessary to accommodate the blower's mounting position in the housing, ambient conditions of the environment in which the device with the blower mounted thereon is disposed, or the needs of specific components in the device. For example, it is sometimes desired to incline slightly the main blowing direction with respect to the axial direction of the blower, or it is sometimes desired to adjust the airflow rate, the air pressure, the blowing sound, or the like.
The prior art includes fans, such as the fan disclosed in Japanese Patent Application Laid-open No. 10-205497, that include a plate at the fan outlet for changing the amount of the airflow and the direction of the airflow. However, such prior art fans are not capable of making all the necessary fine adjustments and they are not cost effective. Additionally, they are not easily adaptable, making it necessary to store blowers of a variety of types with slightly different specifications.